At one time, Gary was using a couple inflatable boat bumpers to roll the boat over the small rocks on Santa Cruz island. I think he used his mainsheet to pull the boat. Larger rock present a different problem. Maybe combine the idea of wood planks, along with some type of rollers and a winch or something similar to pull it with. Either way, it'll ammount to considerable effort to get that 300+ lbs up the rocky hill with one person.
Jack